1. Field of the Related Art
This disclosure relates to an approach for controlling scheduling policies in a multifunctional device environment, and, more particularly, to a system and method for providing for automatic lossless job preemption in a multifunctional device environment by using class-specific scheduling polices.
2. Description of the Related Art
The concept of “network printing,” in which any of a plurality of computers submit digital data to one of any number of printers over a network, is well known. A conventional printing system uses a client/server architecture that usually includes three primary components. These components include (i) a client, (ii) a server, and (iii) an output device. The client conveys print and management requests to the server and receives responses from the server that arise in response to the submitted requests. The server receives these requests from the client, performs the required actions for each request, and returns the responses to the client. One such request from a client is a print request, i.e., a request to print one or more copies of one or more documents, with the printed pages output using one or more features. A print request may represent a collection of one or more documents to be printed, as well as instructions for printing. The server organizes the documents indicated in the print request submitted by the client into a print job. The server then sends the print job and any associated job control commands to an output device.
The output device is a physical device, or hardware, that is capable of rendering images of documents and producing hard copy output of the print jobs received from the server. The output device can then return responses to the server regarding its current state or the status of the received print jobs. The output device is commonly a printer. However, the output device may also be any type of multifunction device (MFD).
In general, a MFD operates as a plurality of different imaging devices, including, but not limited to, a printer, copier, fax machine, and/or scanner. In recent years the basic office copier has evolved into what can be referred to as a MFD. With digital technology, a machine with the basic outward appearance of a traditional copier can perform at least the additional functions of printing documents submitted in digital form over a network, sending and receiving messages via facsimile, recording hard-copy original images in digital form and sending the resulting data over a network, such as in electronic mail and/or recording hard-copy original images in digital form on a compact disc or equivalent medium.
In the area of digital printing and copying, there has been a growth in demand for MFDs. Such MFD devices may assume the form of an arrangement in which a single print engine (e.g., xerographic or thermal ink jet print engine) is coupled with a plurality of different image input devices (or “services”), with such devices being adapted to produce image related information for use by the printer or transmitted over a network. The image related information, in one example, could have its origin in video facsimile signals, microfilm, data processing information, light scanning platens for full size documents, aperture cards, and microfiche. MFDs provide a broader range of functionality than traditional single-function devices, such as dedicated printers, copiers, and scanners. As a result, since MFDs are universally used, it would be useful to enable task/job distinguishment/discrimination among a plurality of MFDs and to treat such tasks/jobs associated with the MFDs differently based on a variety of factors, such as priority schemes.
For example, some single-MFD and/or local jobs are submitted directly to an MFD. Other jobs, such as large optical character recognition (OCR) jobs, are very resource and time consuming and often take several minutes to complete, particularly for complex documents. The MFD receiving the jobs needs to complete both kinds of jobs (the former is run locally and the latter in a distributed fashion) in a timely fashion. In such environments, priority schemes are useful—as local single—MFD jobs can be provided the complete set of resources of the MFD while a copy of the OCR jobs can be safely dropped because of replication schemes that will guarantee completion.
While it is known that MFDs are idle for high percentages of time, thereby wasting good computing resources, MFDs, on the other hand, also need the collective totality of those resources for intensive image/document related processing during the busy times, thus operating together on various kinds of tasks. It is thus desirable to better distinguish/discriminate between tasks processed by one or more MFDs connected to a network.